Landslide Susceptibility Mapping for Shirin-darreh Dam’s Reservoir using Fuzzy Analytical Hierarchy Process and GIS

Abstract

Landslides are one of the most important natural hazards that occur widely in the dam's sites as well as dam's reservoirs. In this regard, the landslides susceptibility assessments for dam's reservoirs can be utilized to estimate the floods risks, dam failures due to slope instabilities in reservoir. Additionally, obtain the hazard risk potential in dam's reservoir capable to investigate the risk-able zones and categorized prone areas to land-sliding. For this purpose, the present study has tried to use a combined computational model based on fuzzy-hierarchical approach (FAHP) and geographic information system (GIS) to assessment of landslides susceptibility and hazard zonation in Shirin-darreh Dam's Reservoir (North Khorasan) to provide the hazard risk potential maps. Methodologically, after identifying the effective factors in landslides' occurrence (including 6 main factors as morphological, geological, climatic, seismic, in-field and susceptible and human parameters), these factors are weighted by FAHP model and layered Information has entered GIS, which has led to estimates of areas with high to low landslide risk sensitivity. Based on the results of the evaluation, it has been determined that in the peripheral margin of the southern and upstream part of Shirin-darreh dam, it has a high slip sensitivity, which can be considered as a dangerous point for dam destruction and flooding downstream of the dam.